Let A be the set of all composites less than 10, and B be the set of positive even integers less than 10. How many different sums of the form a + b are possible if a is in A and b is in B?
1 Answer
16 different forms of
Explanation:
The set
A composite is a number that can be divided evenly by a smaller number other than 1. For instance, 9 is composite
The set
We're now asked for the number of different sums in the form of
In one reading of this problem, I'd say there are 16 different forms of
However, if read as "How many unique sums are there?", perhaps the easiest way to find that is to table it out. I'll label the
And so there are 10 unique sums: